1. Field of Invention
The present invention relates to an image warping software algorithm for a real time alteration of a display scene running under the Microsoft Windows Operating System. The image warping software algorithm alters the display scene and allows an observer to view the display scene as a single unbroken image when the display scene is distributed across multiple display screens. The purpose of the image warping software algorithm is to significantly reduce the distortion observed at the abutting edges of the joined display screens.
2. Description of the Prior Art
In order to support the high demand for modern electronic devices to be portable, the display screens on the portable devices are continuing to decrease in size. Some examples of portable devices that are decreasing in size are laptop computers, hand-held devices known as a Personal Digital Assistants (PDAs), mobile telephones and devices that combine the features of PDAs and mobile telephones. Increasing the overall size of the user display screen for a given portable device, while maintaining portability, is a goal of all manufacturers. Demand for readable information displayed on portable devices has grown as the amount of data, graphics, web pages, e-mails, picture images, GPS mapping images, personal videos, slide presentations, financial information, and video games are made available for operation on hand-held applications. The information now being displayed, however, is getting harder to comfortably see with the naked eye as the portable devices are configured with smaller displays. This demand has created a need to increase the size of the portable device display area while still maintaining portability. At the opposite end of the demand for shrinking displays lies the demand for larger display formats obtained by using a number of independent display screens joined to display a single continuous image. Specifically, there is a demand to display satellite imagery and terrain information on a wall sized area using high resolution display units.
U.S. Pat. No. 6,927,908 issued on Aug. 9, 2005 to Bernard Stark, attempts to solve the problem of balancing the demand for large viewing areas using a number of conventional display units. However, the Stark invention induces distortion at the image breaks coincident with the edge of each display unit. An image break is the area where one display screen abuts an adjacent display screen.
In addition to Stark, others have derived solutions to somewhat eliminate both the image break and the distortion at the image break. One of these solutions is, to take two display elements and overlay refraction plates. This approach increases the size and weight of the display device and is therefore undesirable for use with portable devices and is undesirable for large wall mounted configurations.
Another solution is, to employ a light guide for each pixel in the display to guide the ray of light from the display onto a viewing surface to obfuscate the image gap. This solution is expensive and therefore undesirable to consumers and manufacturers.
And yet a third solution is to modify the edges of the display screens themselves by bending the display screens at the edge to reduce the edge width to allow two neighboring display screens to be closer together. This solution reduces the size of the image gap between screens but does not avoid it all together and is also difficult to manufacture.
And yet a fourth solution, attempts to solve the distortion problem using video hardware components to perform the image transformation.
Stark's invention is described as a system of individual display units with each display unit having a lens covering to provide optical properties at the edge of the viewing area to reduce the image gap. The purpose of the lens covering is to create the appearance of a seamless image to the observer as the multiple screens are viewed with the single distributed image. By taking advantage of the refraction of the lens covering to fill in any visible image gaps between display unit screens the single distributed image is meant to appear seamless. Although Stark's display system attempts to create a seamless image across the joined display units, there are undesired optical distortions in the image at the image breaks.
BAE Systems has attempted to eliminate the distortion present in Stark's display system by developing an offline image seaming software program. BAE Systems' solution is to capture an image and perform a best fit transformation based on the content of the image. Once the best fit transformation was performed, the image was saved as an intentionally distorted image. A user would then take the intentionally distorted image and display it onto the multi-display screen system, manually aligning the image's intentionally distorted areas to the seams of the display screens. This transformation and alignment counteracts any distortion due to the presence of the lens thus eliminating the distortion. Each time a change or modification is performed on the intentionally distorted image, the intentionally distorted image then underwent a subsequent best fit transformation, followed by a newly transformed image being saved, then displayed, followed by an alignment task. Also, each time a user wanted to display an entirely different image the user must perform the best fit transformation process then properly align the intentionally distorted image to the seams of the multi-display unit system. Another drawback of the BAE solution is that once the intentionally distorted image was created it was only compatible with the multi-display unit configuration for which it was aligned. The intentionally distorted image could not be routed to a display configuration that was not identical to the configuration for which the best fit transformation and alignment were performed. The BAE solution is not performed in real time, is processing intensive, cannot process a video stream and is only useful for a fixed set of display units.
Accordingly, there is a need for a real-time software solution to significantly reduce the distortion present when using the Stark lens system. There is a need for a software solution that includes: allowing the user to input control settings for a multi-display system, using the settings to control software execution, formatting an image in real time according to user control settings and is capable of handling a video stream and can operationally display the image in real-time using Stark's cover lens invention while significantly reducing the distortion inherent in Stark's cover lens invention.